<html>
	<head>
		<title>Teste DOC</title>
	</head>
	<body>
		<ul id="lista1"><li>item 1</li><li>item 2</li></ul>
		<ul id="lista2"><li>item 3</li><li>item 4</li></ul>

		<button onclick="mover()">Mover</button>
		<button onclick="mover2()">Mover2</button>

		<script type="text/javascript">
			function mover(){
				x = document.getElementById("lista1").lastChild;
				document.getElementById("lista2").appendChild(x);
			}
			function mover2(){
				x = document.getElementById("lista2").lastChild;
				document.getElementById("lista1").appendChild(x);
			}
		</script>
	</body>
</html>